Good thread.
There's not much in life that would make me use the term 'hate', so it seems a bit excessive to use the term when referring to fictional characters. Ironically though, it almost makes it easier and less vitriolic
because they are fictional characters.
So I'd have to say I
HATE, HATE, HATE Jack, Kate and Juliet with enormous passion. I utterly despise them, everything they say, everything they do even when they're not saying or doing anything. It infuriates me beyond belief that Jack and Kate are the shows'
'leading' characters and that contributes greatly to my hatred. In a show with such superb acting talent, I find it wholly offensive that they are considered the leads. I despised Jack from The Pilot. I find him abhorrent in every possible way, from the way he's portrayed by Matthew Fox, to how totally devoid of personality or interest he is on every. single. level. His character arc is trite and even though we know we'll have to tolerate him for some time into the future, if not until the bitter end, finding out more about his specific journey is purely a means to an end for me. Also, in aesthetic terms he makes me
and I think only Mick Hucknall produces a worse physical reaction from me. My disdain knows no bounds.
Basically Kate instills the same emotions as the above, although the shallowness of her character and her being a complete cow add to it significantly.
As for Juliet, her saving grace is that she's not as bad as the other two. I think it has helped and hindered her in equal measures to share so many scenes with the wonderful Ben. On the one hand the level of interest has been heightened by this interaction but at the same time she pales into insignificance in his shadow. She's been greatly let down as a character with the creation of the whole Jack/Kate triangle thing. It was unnecessary and somewhat lessened her ability to impact as a strong independent character. Oh and also I get a perverse satisfaction from hating JB's favourite character too because the Locke hate gives me sleepless nights....
(
I'm jokin JB 
)